What color/temp do you forge high carbon steel ?

[Ray Plank]

I've only been forging for a couple years, and mostly on low carbon steel. I have been told by several people that when you work high carbon, you keep it very hot, cherry red to yellow, but not so hot that it disintegrates. I tried making a spear head out of leaf spring, and to harden it, brought it up to non-magnetic and quenched in water. It developed the prettiest set of cracks you ever did see ! ( actually, one little tap and it broke right in half ! ) The guys at the guild said I had worked it too cold. Could be, I don't know. THEN, one of the new members of the guild ( who is actually a trained bladesmith ) did a demo on making a knife out of leaf spring, and was very careful to Never take it above the non-magnetic level, and did some work at a black heat. He brought it up to heat very slowly and carefully, and worked mostly in the dull red range, and warmed up the quenching bath before he hardened it. He had the knife at the next meeting, and spent most of the meeting chopping on a hickory wheel spoke to prove its' edge. Is the forging temp different for different aplications? Did I just misunderstand the first guys ?

[Rich Hale]

Ray welcome to smithing. And what you mentioned about different techniques with different steels may be somewhat true. Kind of a vague answer?....Lets first look at Spring steel. I work only with new bars of steel as I know that up front there are no stress cracks in it and I can be sure it is the steel I wanted to use. A starting point wouild be to bring it up to non-magnetic and see how it moves. while remembering the color at that heat. If it will move nicely at a heat just under that,,a bit darker color I will go with that, If not go back to the color of non-magnetic. Different ambient lighting and different interpretations of colors make it really tough to go by what other folks say a color should be. Dull red in day light may look really bright at night. I cracked a real nice blade in too cool of quench oil. A great way is to take three pieces of the stock you are forgeing and bring them all up to heat. let one air cool. one in 120 degree oil and one in same temp water. Premark them clearly so you do not mix them up after quench, Temper each the same and test them. Then should take and hold an edge,,,they should bend and return to shape. This simple rudimentary testing will sort them out really fast. Have fun

[Ray Plank]

Thanks for the info Rich. So far I've been playing with used coil springs and leaf springs from the salvage yard. (I'm cheap ! ) If I understood you right, you recommend working it as close to the non-magnetic point as possible, which in my shop is a dull red to light red, rather than taking it way up to the yellow ? I'll definitely try the quench test you suggested.

[irnsrgn]

Ray for what its worth, non magnetic is approxiametly 1460 degrees, steel starts to scale at 1550 degrees, this does not rely on color but on scale forming, so if its scaling you have it too hot.

irnsrgn

[sandpile]

Hello RAY: What Rich and JR. are talking about is called cold- forging.
When you take it up to the heat that you want and the scale is very fine and small, you are alright. Under 1600 degrees.
I will take the spring steel to the full red and if I can move it around like I want, I will not get it any hotter.
There is a lot of steel over heated by not knowing why, you have to work it at the lowest heat possible. If you take it up to high, you burn the carbon out it. You will be having large pieces of scale some as big as your thumb nail.
I like to drop a couple of hot pieces in the quenching oil and bring it up to 135 Degrees. This seems to be where the 5160 likes to quench.
After this has been done two or three times you start your tempering.
After quenching you need to draw it back, I use 350 to 375 degrees for the tempering heat, for two hours soak. I will also temper several times. Quenching after each temper cycle, in water.

Sandpile

[Ray Plank]

Ok, so probably what cracked my spear head wasn't forging it at too low a temp, but quenching in icy cold water. ( It was December )

This is starting to make sense. Keep the steel warm enough to move fairly well but don't over heat and loose carbon. An alternate way of gageing temp is by how the scale is forming, small and fine is near non-magnetic, large chunks is too hot and carbon is being lost. Warm up the quenching bath to around 130 degrees F, and temper several times, or let it soak at a preset temp for a couple hours. ( I'm getting an old toaster oven to use for tempering ) Am I understanding what you guys are saying ? I really appreciate your willingness to share your knowledge, and want to make sure I get it right.

[sandpile]

RAY: How are you tonight. I should have added a little more to the post. You need to quit beating when the steel quits moving. It is very easy to crack carbon steel, by beating on it after it loses its heat. I try never to hit any steel after it loses all of its color.
The tempering cycles are just as important as the hardening cycles.
As you become more familiar with the forging of blades, you will need to know about normalizing and annealing. There is a good piece written by RF NICHOLS in the blueprint section of this site. I think it is B0078 or something. If you would have about three reads on his article, you would understand a lot more of the jargon that goes on around here.
It is a little different with thinner blades but is still the right way to learn. We will do triples in the normalizing and hardening and the tempering, where as in the steel industry this is not done as often.---GOOD LUCK.

Sandpile

Metallurgy of Heat Treating

[JPH]

Ray:

From somebody who's done this a little while...

There are serious problems that arise with the way you said you did that spear head. It's not the temperature that you worked it at, it is the fact that you water quenched a oil hardening steel. That will crack the steel 999 times out of 1000.

Add the fact that you are using a recycled leaf spring, something that you have no idea as to its condition, you are setting yourself up for failure. Used leaf spring can be decent but I would rather not use them for anything with my name on it! They can have micro-cracks and a host of other problems that can cause you heartache.

On the forging temps. On a "high performance" piece I will work UNDER the transition tempo for that particular alloy. granted I am working harder than most but I feel the end product is better for not having to worry about grain enlargement. Couple this with proper thermal treatment and you get a very good blade.

On other stuff like PW materials...I tend to start working at a welding heat right after I do the last weld in the course. I will work the piece under my LG until it is a solid cherry red and then it goes back in the forge to get hot and the process starts all over again.

Now for what you are doing I would comfortably say work hotter...a bright cherry up to a yellow would be ok for the heavy forming. Coil springs are usually 9260 and I have played around alot with that steel lately and it is a good steel for "impact" uses. Here again though, using a recycled material you run the chance of having problems due to the condition of the material.

Anyway what ever you do use an oil quench not water!!

hope this helps..

JPH

[Ray Plank]

Sandpile, Yes, it is Blueprint number B0078. Thanks. You're right, It'll take a couple reads. ( especially for me ! grin )

"Don't quench oil hardening steel in water." Makes sense ! I know there are "air hardening" steels out there, are there any that you are SUPPOSED to quench in water, or should I just quench everything in oil ?

Thanks again for all the shared knowledge !

Ray

[yesteryearforge]

yes there are water hardening tool steels
they generaly start with a W as in W1 just as oil hardening start with an O as in O1 O2 etc.

[JPH]

RP:

As to the question on water hard steels...these are usually preceeded with the letter "W" as in Water. Also you can use WHC and well as 1045/1050. Anything over 1055 I would NOT suggest hardening in water, even thought the mill specs say 10xx series steels are "water hardening".. the mills don't factor in blade cross sections for some reason.

Now I wouldn't use plain water. When I work a water hard steel I harden in my caust blue tank at 285F. This tends to shock the steel alot less and makes a very nice hardening quench. Right after the blade is hardened I temper immediately.

Since you do not seem to be all that familiar with the various steels I suggest you read all you can on this. In the mean time, in a nut shell you have:

Water hardening steel, these are the W and the lower 10xx series

Oil Hardening steel, these are the higher 10xx series, O-1, L-6 and a host of others.

Air hardening steels like A-2, D-2, M-2..alot of high alloy steels here. If you know how to work these, these make excelent blades.

Percipitation hardening steels (really weird materials) like 17-4 PH...

The mill specs for hardening are really easy to read actually and knowing what hardens in what can really save you some heartache.

If you get stuck, drop me a line and I should be able to help ya out a bit...

JPH

[sandpile]

FIRST; JIM, I am glad to see you back...
I have been fooling with some blades made from 1 1/2" ball bearings. All of these bearings came out of the same gear-head on an irrigation pump. I assume it is 52100.
I have had varying degrees of success with the heat-treat on the blades. I am in the process of testing one right now. I have flex tested it and it did flex and did not break or chip. Resharpened past the flex depth. Cut some rope several times with the same spot on the blade. Chopped a fourXone inch board in to and it still will cut hair off your arm. I am going to put it in the vice and pull it over to see where/if it fails.BOG. I want it to go to a 45 degree bend and go back to straight.grin. I will then continue to a 90 degrees bend and see if the edge cracks.
This blade was diffi.(sp) hardened, with a torch. Just the bottom third and the tip. I triple tempered at 350. No cyro. The blade is 5 inches long and 1 1/8" deep and 1/8" thick
More later

Chuck

[Ray Plank]

JPH. You're right. I need to start reading. I just picked up "The Wonder of Knifemaking" by Wayne Goddard. Are there any other titles you would recommend ?

Ray

[Ed Thomas]

Ray,

Do a search on "Jim Hrisoulas" and just take your pick of whatever books he wrote that you want to know about. That's who 'JPH' is. It is a privilege and an honor to have him check in here and share what he knows so freely.

[JPH]

Chuck:

52100 would be my guess on those ball bearings. I'd say that 99% of the time that is what they are. I have played about with the stuff a bit, but I am pretty well set on the 10xx series, the 51xx series and the 92xx series and a few others like M-2, L-6 and the old Vascowear (when I am feeling self abusive). I know these steels inside and out and well, they do all that I want from a blade steel. Still it is fun to mess about with different stuff every now and then. What did you harden it in??

Ya know alot of folks don't realize how badly you can screw up a steel with improper forging. If you don't know the proper temp ranges you can really mess yourself up. Still these folks believe that simply because a blade is forged that it makes it that much better. Sad to say that is not the case. Thermal treatment is what really makes the difference between forged and just ground. Now PROPER forging coupled with the PROPER thermal treatment, there is where you get the performance differences.

Sounds like you done it right with you little shiv there. At 1/8" or so thick that should flex no problem and hold together.

Ray: After the bruhaha last time I would rather not recommend any books. Seems some thin skinned folks raised a ungodly stink last time and I do not care to have that repeated...

Ed: Ya know..you sure ruined my fun...rained on the parade...all that other stuff. I was kinda enjoying the fact that RP was a neophyte and all. Yet another mind to corrupt. Well he would of found out sooner or later but I wasn't going to tell him. Whahahahahahahaaaaa!!!!


Anyway I am back to gimping around...

JPH

[Glenn]

After the bruhaha last time I would rather not recommend any books. Seems some thin skinned folks raised a ungodly stink last time and I do not care to have that repeated...

For reference: The "bruhaha last time"

There were some comments made that were "out of place" and resulted in an individual being banned from the site.

I expect everyone to be gentlemem and ladies and will tolerate no less. You can discuss all you wish on any subject. You can politely question the information given, but no one will come under a personal attack. There will be no ego trips, and no flame wars. It is not going to happen.

IForgeIron and the Blacksmith Forum are family sites and everyone is welcome to view the information, and to contribute at any time.

If you see anything that is out of place, or objectionable, on the IForgeIron sites or the Blacksmith Forum, please contact a moderator, or contact me directly so we can look into the matter.


Again, I expect everyone to be gentlemem and ladies and will tolerate no less.

Glenn


I must add just as quickly, that the viewers and contributors have been wonderful. It is a pleasure to provide a site for their use.

[sandpile]

HELLO JIM: I am a novice forger with 52100.
There has been a great deal of testing done by Bill Burke and Ed Fowler and a metalogist by the name of Ray Walter. They have been more than gracious with their advice and experience.
If you are familiar with their methods, that is how I have done my complete forging/heat-treat.

I never let the metal get over 1550, while forging the blade. Triple normalized, annealed. I just hardened the bottom third(non-mag) of the blade in 165 degree, mineral oil from Texaco. I did this three times and etched to see where my hardness was going to be. The blade was still thick as this time. I finish ground it and put it in the oven for the first of three tempering cycles at 350 . Re-etched and it seemed like the temper lines were where they needed to be.

The only hemp rope I had was oily and really hard to cut, so did not get a good idea of how it was going to cut. I then chopped a 1"X4" board into, it would still cut hair. Put it in the vice and bent it to about 45 and nothing cracked and it went back to shape. Success finally.BOG

I am working on one now that the entire blade was hardened and the spine drawn back with tempering tongs per Nick Wheeler. I am tempering the blade in the oven.Hopefully this will work a little better. I don't like the hit or miss of hardening with a torch.BOG.

Thanks for your interest.

Chuck

[Ray Plank]

JPH, My apologies. I certainly didn't mean to put you in an awkward position. Thank you for sharing your knowledge with us. Now, I have some reading to do. ( grin )

Ray

[JPH]

Chuck:

Well by the sounds of it, you must of did something right as far as thermal treatment. These carbon steels can really perform once you know what they need to do it.


Ray: Appology not needed. If you can get ahold of any of the old (and new) Machinist's Handbooks there will be ALOT of info in there but you better have decent eyesight cause the print is TINY. The is so much to learn about doing this that it is hard to find a place to start from. Knowing what a steel does and needs is probably one of the better places to start.

If you need anything, drop me a line...

JPH

[Beomin2306]

Your problem, most likely, is quenching in water...  NEVER quench in water, even quenching in oil you want the oil to be hot, because if what you quench it in is too cold (water) it will shock the metal and cool it TOO rapidly creating cracks and making it very brittle.